Process for cracking oil



Au 9 1927. g G. EGLOFF PROCESS FOR CRACKING OIL Origin a1 Filed Dec. 20

Patented Aug. 9, 1927.

UNITEE STATES PATENT OFFICE.

GUSTAV EGLOFF, OF

UCTS COMPANY,

INDEPENDENCE, KANSAS, ASSIGNOR TO UNIVERSAL OIL PROD- OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA.

PROCESS FOR CRACKING OIL.

Application filed December-20, 1920, Serial No. 432,071. Renewed January 3, 1927.

This invention relates to improvements in a process for cracking oil, and refers more particularly to a process in which the 011 is treated in a battery of heating elements, each provided with its own expansion chamber, and the generated vapors conveyed from the respective expansion chambers to a common vapor drum, and thence subjected to reflux condensing action. The process is also dis tinguished by the fact that the oil is subjected to differential pressures in various parts ofthe system, and more particularly to a constantly increasing pressure whereby the oil, particularly the vaporized portion thereof, has its constituents subjected to amore intense, impact of the molecules, thus tending to facilitate and speed up the reaction at the same time producing difierent products of reaction than would be the case where lessened pressures were employed. At the same time the process is so carried out as to avoid subjecting that portion of the apparatus which is heated to undue temperature conditions.

In the drawings, the single. figure is a somewhat diagrammatic side elevation and "ertical section of my improved apparatus.

Referring to the drawings, 1 designates a furnace construction in which is mounted a battery of heating elements 2, each of which may take the form of say several hundred feet of two to six-inch pipe. The inlet side of each coil connected to a main feed header 3, leading to the raw oil charging pump 4, which pump is connected to any suitable source of supply. The outlet side of each heating coil is connected to a relatively large shell-like vapor chamber 5 located outside of the fire zone, each vapor chamber being provided with a residue draw off pipe 6, having throttle valve 7. The upper part of each expansion or vapor chamber 5 is provided with a vapor outlet pipe 8, leading to'a vapor header 9. This vapor header 9 is connected by transfer pipe 10 to an elongated relatively large vapor drum 11. A pump 12 is interposed in line 10. The upper part of the drum 11 is connected by pipe 12 to a dephlegmator 13, having bafiles 14. The upper part of the dephlegmator 13 is connected by vapor outlet pipe 15 to the condenser coil 16, seated in condenser box 17. A pressure pump 18 is interposed in the line 15. The lower end of the condenser coil is connected by pipe 19 to the top of receiver 20. This receiver 20 is provided with gas outlet ipe 21, having throttle valve 22, liquid raw oflt' pipe 23, having throttle valve 24. It also has liquid level gauge 25. Various parts of thesystem are provided with suitable pressure gauges 26 and with pyrometers not shown. Throttle valves 27 are interposed in the connections leading from the heating coils to the feed header 3, and similarly valves 28 are interposed in the various feeder lines 8. The reflux condensate may be drawn off from the lower end of the chamber 11 through pipe 29 leading to raw oil pump 4. If desired, the retiux condensate may be drawn 05 elsewhere through the branch 30, valves 31 and 32 being provided as shown for this purpose.

The process may be carried out as follows:

Raw oil, as for example, fuel oil or heavy Mexican or California crude oils or crude oils from foreign fields, may be fed continuously through the main header 3, and thence into the respective heating coils and corresponding vapor chambers 2 and 5 respectively. Here the oil may be subjected to a pzessure of say 150 pounds and heated to a temperature in the heating coils of say 700 degrees F., the valves 27 and 28 being open. The residue is constantly drawn off through pipes 6 while the vapors pass out through the pipes 8 into the header The vapors are pumped by means of pump 12 into the elongated vapor drum 11, and subjected in such chamber 11 and dephlegmator 13 toa pressure of say 200 pounds. The vapors are passed out of the upper part of the dephlegmator and these may be finally condensed under a pressure of say 300 pounds by suitably operating the pump 18. t 15 to be noted that the vapors are before entering the dephlegmator collected in the common vapor rum 11. This drum is relatively long so as to cause the vapors to have a substantial travel therein before they can pass out of the chamber 11, and inasmuch as they are subjected to an increased pressure, not only a more pronounced but a more prolonged impact of the molecules of the vaors is obtained, this impact resulting in facilitating the reaction. It is to be understood that the various lines 8, 9 and 10 may be insulated so as to deliver the vapors at a relativel high temperature into the chamber 11. y means of this process some 50 to per cent of the raw oil charge may be converted into high grade pressure distillate containing substantially large percent ages of gasolene. Inasmuch as the chamber 11 is located outside the fire zone, it may be subjected to a very much higher pressure than the stills themselves, as' for example, a pressure of say 150 pounds on the still and 1.000 pounds on the chamber 11 and dephlegmator, and even 1,500 pounds on the condenser coil and receiver. If desired, the pump 18 may be bypassed through the bypass line 33, having throttle valve 34, 'by opening this valve and closing the other valves 35 and 36.

I claim as my invention:

1. A process for cracking oil, which comprises subjecting oil to cracking conditions of temperature and pressure, in passing the oil into an enlarged expansion chamber from which vapors pass to a vapor drum and .thence to a dephlegmator, in maintaining the vapors in said vapor drum and in said dephlegmator at a superatmospheric pressure exceeding the pressure under which the oil was distilled, and in finally collecting and condensing the vapors passing from the dephlegmator.

2. A process of cracking oil, consisting in passing oil in a stream of restricted cross section through a furnace to be subjected to cracking conditions of temperature and pressure, in introducing the oil from the stream to an expansion chamber and in maintaining a pressure thereon substantially equal to the pressure maintained in -the stream, in discharging the vapors from the. expansion chamber to a .second enlarged chamber communicating with a dephlegmator, and in maintaining said vapors in said second chamber and in said dephlegmator under an increased superatmospheric pressure.

3. The process of cracking hydrocarbon oil, which comprises passing hydrocarbon oil through a plurality of independent coils,

in delivering the oil from each coil to an associated enlarged expansion chamber, in heating the oil While passing through the coils to a cracking temperature, and in maintaining the same both in the coils and in the expansion chambers under a superatmospheric pressure, in discharging vapors from each of said expansion chambers into a single elongated vapor drum, in passing vapors from said drum to a dephlegmator, and in maintaining a superatmospheric pressure in said drum and in the dephlegmator in excess of the pressure maintained in said coils and expansion chambers.

4. A process for cracking hydrocarbon oil, which comprises subjecting the oil to cracking conditions of temperature and pressure, in delivering the heated oil into an enlarged expansion chamber, in passing vapors evolved from the oil to a vapor drum, in subjecting the vapors in said vapor drum to a pressure in excess of the pressure maintained in said expansion chamber, in thereafter subjecting the vapors to dephlegmation in a dephlegmator, and in finally collecting and condensing the Vapors passing from the dephlegmator.

5. A process for cracking hydrocarbon oil, which comprises subjecting the oil to cracking conditions of temperature and pressure, in thereafter passing the oil into an enlarged expansion chamber, in passing vapors evolved from the oil to a vapor drum, wherein the vapors are subjected to a superatmospheric pressure, exceeding the pressure maintained in said expansion chamber, in subjecting the vapors issuing from said vapor drum to dephlegmation in a dephlegmator, in passing reflux condensate resulting from such dephlegmation to said vapor drum, in removing reflux condensate from said vapor drum, in again subjecting such reflux condensate to cracking conditions of temperature and pressure, and in finally condensing the vapors issuing from the dephlegmator and in collecting the resulting distillate.

6. A process for cracking hydrocarbon oil, consisting in maintaining a battery of units, each comprising a heating coil and expansion chamber, in subjecting a stream of hydrocarbon oil to a cracking temperature while flowing through the heating coil of each unit, in delivering the heated oil from each coil to the expansion chamber of the associated unit, in passing the vapors evolved from the oil to a vapor drum, wherein such vapors are subjected to a superatmospheric pressure in excess of the pressure maintained on the oil undergoing treatment in said units, in thereafter subjecting the vapors to reflux condensation, in returning the reflux condensate separated from the *vapors to the heating coils of said units, in finall condensing the vapors, subsequent to re ux condensation, and in collecting the resulting distillate.

GUSTAV EGLOFF. 

